Building the Nathan 10 - Page 3 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 31st July 2008, 03:37 PM   #21
Fosti is offline Fosti  Germany
diyAudio Member
 
Fosti's Avatar
 
Join Date: Jun 2006
Quote:
Originally posted by pjpoes



There is nothing anachronistic about a passive crossover. The concept and implementation is, at its essence, not much different from an active crossover. While there are certainly benefits to a multi-amped system using active crossovers, when it comes right down to it, you are still crossing over an electrical signal in essentially the same manner, through the use of LCR based filters....
A lot of words, that may lead some people to the belief that this is so, but.....everyone can read about that topic in good books. Only so much: The probably best studio monitors in the world are active (and German ): Look for the MEG RL901
or
K+H O500C

Quote:
Originally posted by pjpoes


Dr. Geddes, .....
It's polite to honor someone for his scientific reputation, but gedlee is not the only one with a PhD here in the forum....some may be even a Dr.-Ing. (<-- that's German, too)
__________________
"... they don't know what they do." - Thats right, quite often!
"... they don't do what they know." - That's right, even more often!!!
  Reply With Quote
Old 31st July 2008, 03:51 PM   #22
Banned
 
Join Date: May 2008
Location: Switzerland
Quote:
Originally posted by gedlee As to the MDF not being very dense - well I question that comment as I have never seen any that is any different.
Actually I brought some MDF with me when moving to the States. It's a lot more dense. Bought it at OBI in Germany which is similar to Home Depot. You even can get different qualities in Germany. I can't imagine that it's any other over here?

Quote:
Originally posted by gedlee The foam used to pack the materials is the internal damping - I hope that you didn't throw it away.
No still have it.

Quote:
Originally posted by gedlee The screws for the crossover terminals should have been in the kit.
No, these are all screws I found in your package:

Click the image to open in full size.

Quote:
Originally posted by gedlee And I seriously hope that you are not going to roller on the Behr paint.
I asked the guy at Home Depot for the best water based acrylic paint they have. This was his recommendation. He also said that there's no latex in it. But if this is the case I would never want to use it. What acrylic lacquer would you (and the others) recommend? It should give good results when applied with a roller.

Quote:
Originally posted by gedlee The MDF thickness does vary, but on my samples its never as low as .75" and thats using a micrometer.
Measured mine with a micrometer as well. Again, in Germany there's no variation in thickness. Either you buy 19 mm or 21 mm. These are simply differnet types.

Quote:
Originally posted by gedlee You got a kit with two enclosures in one box, right? I don't do that anymore because it was too heavy and would tend to get damaged.
Yes, one box. Some boards got damaged because you just put them loosely in the box, e.g.:

Click the image to open in full size.

Quote:
Originally posted by gedlee Those parts are not cut on a numerical machine, which is what everybody uses these days, they are all cut by hand and there is going to be some variation.
Would you call this a variation?

Click the image to open in full size.

The picture was taken AFTER I straightened the inner board of the baffle. Now the top and side boards line up nicely to the front. But the side parts are simply 3 mm to low!

Quote:
Originally posted by gedlee To have them cut by machine would push the kit price up substantially. Is that what you want?
That is an option I would definitely recommend to unexperienced hobbyists.

Quote:
Originally posted by gedlee The fact is that it is no problem assembling the enclosure to a fine fit if you are somewhat experienced with a sander and some filler as the photo below will show.
Sorry, but you compressed the image too much for any details to be visible.

Quote:
Originally posted by gedlee If you are looking for precision to .5 mm then this is not a kit for you.
I was not talking about 0.5 mm but 2 mm. And it's not the cut (except for the side parts) but how the two boards forming the front baffle were glued together.

Best, Markus
  Reply With Quote
Old 31st July 2008, 04:07 PM   #23
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
The fit on the top is due to two things. First you need to push up the side board so that it fits snuggly into the dado - thats not done. Second the side panels are not routed and as I said, there will be an overhang on the sides - you have to sand this off to a smooth round corner.

I didn't buy the MDF in Germany - here I have only seen one kind.

I must have forgotten the smaller screws - sorry about that.

Marcus, you made no qualms about being "in a hurray" and as such I raced to get yours out first. There are going to be some glitchs that will get fixed down the road. Had I known that you were going to trash the kit I would not have made the extra effort to get your kits to you first. Lets wait and see what others say before jumping to conclusions.

Someone who is not competent at assembling hand-cut wooden enclosures should not buy this kit, to that I would agree. But anyone who has even the slightest experience with building a box will have no trouble accomodating the kind of things that you are complaining about. I'm not making excuses here and as time goes on the parts will get better, they are already better, but being the first means that you see all the startup problems.

You have to remember that this whole project started less than four moths ago. To go from concept to shipping, single handedly, in four months is no small feat. There will be growing pains.

If you are so displeased then send it back and I'll refund your money.

Here is a pic as good as I can get with my camera.
Click the image to open in full size.
  Reply With Quote
Old 31st July 2008, 04:11 PM   #24
diyAudio Member
 
Join Date: Apr 2007
Earl,

It seems like mating the baffle roundover to the rounded edge on the top panel is a lot of work for what is IMO most likely only aesthetic benefit. The real acoustic benefit is the roundover on the baffle edges.

My suggestion would be to eliminate the the roundover on the top cabinet panel so that the amount of work the user has to do to assemble the cabinets is much less. Which also means less chance of someone screwing up the front baffle and waveguide which is really the expensive/critical part of the cabinet anyway.

Kind regards,

Dennis
  Reply With Quote
Old 31st July 2008, 04:19 PM   #25
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
Dennis

The top edge is less critical for diffraction, but I still think it important. And yes, it is the hardest edge to get right, but its still no problem to get right as my photo shows. As I said we need to see what other builders think as Marcus seems to be pretty picky.

You will notice from my photo that the rounded edge DOES have to be sanded down into the side panels. This is to be expected. Sanding this by hand may be somewhat tedious, but with an inexpensive sander it only takes about a minute to get right once everything is glued together.
  Reply With Quote
Old 31st July 2008, 04:26 PM   #26
Luke G is offline Luke G  United States
diyAudio Member
 
Join Date: Apr 2007
Agreed, it seems like it would be much easier to crank these out without roundovers at all and then let the end user add a roundover if they desire.

*EDIT: Just saw Dr. Geddes response that the front baffle roundover is important, nevermind.



I'd even be fine with just getting the front baffle and a simple cut sheet for the other parts. That would save on labor and shipping for Dr. Geddes. Is this possible?
  Reply With Quote
Old 31st July 2008, 04:45 PM   #27
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
Yes, this is an option, but it requires a table saw and thats not a common piece of equipment. The baffle rounover is extremely important and it should be as large as practical. A 1" router bit is just about as large as feasible and so this is what I use. If anyone wants their kits without a radius on the baflle then thats fine, but it should be radiused when completed. The tool to do this is also not typical (a 1/2" router and 1" radius bit). But if you have those tools then by all means order the kit without the radiuses and then put them on after assembly.

However, once again I'll say that I have built four of these enclosures and I have no trouble with the edges at all. I prefer a very loose fit enclosure as it is far easier to fill gaps than correct something that is too tight. It is best to have a palm sander for this, but that's a very inexpensive piece of equipment - unlike a table saw and router.
  Reply With Quote
Old 31st July 2008, 04:50 PM   #28
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Dr. Geddes sold one of his first kits with teething MDF precut problems to a German client! And he is telling him that precision ISN'T a big deal.

Yes he will accept it right away! He is used to it. Dr. Geddes you aren't particularly lucky.
Attached Images
File Type: jpg carreragt06.jpg (21.0 KB, 1044 views)
  Reply With Quote
Old 31st July 2008, 04:56 PM   #29
Banned
 
Join Date: May 2008
Location: Switzerland
Quote:
Originally posted by gedlee
First you need to push up the side board so that it fits snuggly into the dado - thats not done.
What happens when you push the sides to the top? The base will be not straight on the base sides...
Does the base of the enclosure need to be rounded too because of acoustical reasons?

Quote:
Originally posted by gedlee Second the side panels are not routed and as I said, there will be an overhang on the sides - you have to sand this off to a smooth round corner.
But the overhang varies just too much because of the two boards that form the baffle not being glued straight. So the enclosure itself won't be straight. One would see that clearly when the speaker is finished.

Quote:
Originally posted by gedlee Marcus
Sorry for being off topic, but I don't understand why every American insists on writing Markus with a "c". My name is spelled with a "k". Just out of politeness I always try to spell someones name right.

Quote:
Originally posted by gedlee Marcus, you made no qualms about being "in a hurray" and as such I raced to get yours out first. There are going to be some glitchs that will get fixed down the road.
I thought I said thank you in one or two of me emails, but to make it official: "Thank you!"
Beside of that, someone being in a hurry shouldn't lead to ship a product with flaws?

Quote:
Originally posted by gedlee Had I known that you were going to trash the kit I would not have made the extra effort to get your kits to you first. Lets wait and see what others say before jumping to conclusions.
This is YOUR conclusion not mine. Never did I trash the kit. I'm just reporting (hopefully in an objective manner) what MY kit looks like and what it takes to assemble the Nathan 10. But conclusions will follow when the Nathan is finished and measured.

Would appreciate if you find the time to answer my last postings questions.

Best, Markus
  Reply With Quote
Old 31st July 2008, 05:11 PM   #30
diyAudio Member
 
Join Date: Jun 2004
Location: Green Bay, WI
Send a message via AIM to John_E_Janowitz Send a message via MSN to John_E_Janowitz Send a message via Yahoo to John_E_Janowitz
Quote:
Originally posted by markus76

I asked the guy at Home Depot for the best water based acrylic paint they have. This was his recommendation. He also said that there's no latex in it. But if this is the case I would never want to use it. What acrylic lacquer would you (and the others) recommend? It should give good results when applied with a roller.
The first thing you need to do when finishing MDF is determine how smooth you want it. Since you mentioned applying it with a roller, I'm assuming you are ok with somewhat of an orange peel texture. That means you don't need your surface as perfect, but preparation is still the key. The on the cabinet you first need to get it sealed fully so that the seams won't be seen again. This is one of the most tedious parts of finishing. I'd fill any large gaps with Marglass or Glasslite, the body filler with tiny fiberglass fibers in it. You can get this at any auto body store. Bondo has one that you can get at Walmart even. A standard auto body filler will crack over time. You need the strength of the fibers to keep seams from coming back. Then sand it as good as you can with 80-120grit. No need to get perfect at this point. Use a board file, straight line sander, or a 12" long sanding block if you have to do it by hand. The key is keeping the flat surfaces flat. Blow everything off well.

Then you'll want to use a sanding sealer to fully seal up the entire surface of the mdf. You need it to be air tight to keep moisture out, or your seams will swell down the road. Also expect the MDF to soak up the material and swell on the end grain with this first applicaiton. Let it fully dry and then come back with an auto body spot filler to fill in any tiny cracks. It will go over the sanding sealer quite well, and once the mdf is sealed it won't shrink nearly as much as if you had done it on raw MDF. Let the spot putty dry, then sand the seams smooth again. At this point the end grain should be sealed up/impregnated with the sanding sealer and won't swell with the next applicaiton. You can use regular polyurethane for this step if you want as well, but it will take longer and not sand as easily. I'd go with 2 more coats of polyurethane over the top, sanding between. If you notice any tiny cracks or pits or holes, come back with the spot filler at any time. Once this is all done, your cabinet is sealed up well, you can scuff it with a scotch brite pad and paint over the top of it.

Another great option is DuraTex. http://www.acrytech.com/store.asp?pid=14119 It's self priming, seals up cracks well, and you can choose a variety of methods for putting it on. It's high build so hides cracks and imperfections well and sands easily with 220grit. Don't go with a larger grit as it will peel and gum up the paper. 220 seems the fastest and gives the best results.


Quote:

Yes, one box. Some boards got damaged because you just put them loosely in the box, e.g.:

Click the image to open in full size.
It is hard to keep kits from getting damaged as shipping companies do drop things a lot. We used to do 2" eps foam around the whole outside of the box, then pack the pieces. We'd shrink wrap the pieces, then cut the eps foam to pack tight and take up any space in the box. It would literally take an hour or more to package up one kit and about $10 in EPS to make sure everything is held tightly in place.

I guess of more concern in this picture than the damage is the inconsistency of how the edges are routered. You can sand out that little line, but it won't change that the whole roundover is deeper in points. The depth of the cut is clearly not consistent. I think the point in offering a kit is because you are giving the customer something that is better made than they could have done on their own. I would expect that as a large amount of DIYers have a lot of woodworking experience, they could easily manage work of this caliber on their own. If you don't have a router table, which is the easiest way to do the edges, make a simple router edge guide. http://www.woodworkingtips.com/etips/etip063000ws.html

This will allow you to adjust the router to the right position and also will help you hold the router flatter when making the cuts. You'll have a consistent cut and not have to worry about the router bouncing at the end of the panels.

Regarding the whole concept of what is acceptable or not, as a manufacturer or retailer it's not up to us to determine what is acceptable to the customer. That is their job, and it is our job to make it to a level they will accept. At a price point of $1200, the kits are already in an area where there isn't a huge market for them. There are some DIYers who really want to build the ultimate system, but also many others who want a bargain. An extra $50-100 per kit to get the pieces cut on a CNC, or align them with pocket hole screws would not deter many people. It has been my experience that those willing to spend $1200 would easily spend the extra little bit of money to get a kit that goes together easily and save lots of time and effort.

John
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 09:51 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2